Alignment of driving and driven components comes up in a variety of applications. One example is a gearbox where a driving gear needs to mesh with one or more driven gears. The gearbox housing is generally horizontally split between and upper and lower housing. At the split the housing halves are formed to accept shaft bearings. When the gearbox is used to drive multistage centrifugal compressors, for example, there may be two or more driven gears that need to be properly aligned with the driving gear. The cutout at the split that accepts the bearing is precision machined and the bearing outer housing is a close fit by design. In the past if adjustments to the position of the driving gear needed to be made after the initial assembly to the gearbox lower housing, there were two main alternatives to make an adjustment. Both these choices required significant trial and error and consumed a lot of time and for that reason turned out to be expensive and uncertain from a longevity perspective. One way to fix misalignment in the past if, for example the bearing needed to be raised vertically was to add material to the lower housing half where the bearing mounts and remove a similar amount of metal above to retain the shape of the opening accepting the bearing but to relocate its center upward. This procedure was done in steps in a trial and error manner to avoid overcorrecting for the targeted center location for the bearing. Another technique was to add shims below the bearing in the lower case half and remove material from the upper case half. Again this process was done incrementally, to avoid removing too much material above the bearing. Using either technique took a lot of time and was costly and still left concerns regarding long term reliability of the assembly maintaining the desired bearing position.
What was needed and provided by the present invention is a way to alter the bearing center position without having to add material and remove material from the housing halves and without resorting to using shims instead of another procedure to add metal to alter the bearing position with respect to the housing. The present invention allows this to be done by providing a bearing center offset from the outer bearing housing center. Should a vertical adjustment be needed, the bearing housing can be rotated and locked into position. The housing halves for the gearbox or other structure where the bearings are mounted does not need to be modified. The changes can be made rapidly saving time and money and the long term reliable running is more assured. Those skilled in the art will appreciate all the aspects of the present invention from the detailed description of the preferred embodiment and the claims, which appear below.